Study On The Water Simulation And Analysis For The Nansi Lake Based On WASP7.3

Abstract: There are many lakes in china. The total area of lakes accounts for 0.8% of the total land area. However, the lakes'water pollution is an outstanding environmental problem which we were facing currently. Under the combined effect of the natural and man-made activity, the lakes in our country have changed dramatically since the 1950s. It causes serious threat to sustainable development of the region.The East-Route of the South-to-North Water Diversion Project is super great infrastructure project which will relieve serious water shortage in north China. It can solve the urban water shortage problem of North Jiangsu, Eastern Shandong, and Southeastern Hebei and along the tientsin-pukou railway. It also can be the supplementary water source of Tianjin City.The Nansi Lake is an important water conveyance channel and storage lake of the East Route Project of South-to-North Water Diversion. Its water quality has been bringing widely attention of the public. The East Route Project of South-to-North Water Diversion can smooth implementation or not, the premise is water-saving, and the key is pollution-controlling. According to the implement opinion of pollution-controlling planning of the East Route in South-North Water Diversion Project, the key problem is the NansiLake to ensure the water quality in main canal reached the classâ…¢of the Surface Water Environment Quality Standard ( GB3838- 2002 ).Based on the mathematical methods and modern computer technology, the paper selects the lower Lake for research demonstration. Considering the examination index of the National Water Pollution Control and Governance of China (NO. 2009ZX072 10-007). According to the Nansi Lake's topographical features and hydrological conditions, the water diversion conditions, hydraulics principle, pollutant transport and dispersion processes, pollutant mixing characteristics and so on, the paper gives the simulation of the distribution laws and distribution characteristics of the major pollutants in the lakes by the method of the Water Quality Analysis Simulation Program (WASP). The paper also predicts the lake water environment quality of the non-diversion period and water diversion period, when enhanced the Nansi Lake basin's pollution prevention efforts. The research gives the studies on the risk pollution sources'recognition of the the Xuecheng Small Shahe Control Unit. This research also analyzes and evaluates the water quality of any environmental pollution emergencies calculation cases in the lower lake, the nutritional status in Nansi Lake and the hazardous chemicals in Nansi Lake.Through research and a nalysis, we draw the following conclusions:(1) According to the water quality monitoring data of the Nansi Lake, the paper studies on the model applicability of WASP7.3 in the Nansi Lake. The results show that the standard deviation and variation coefficient of the model index accord with the model requirements. WASP7.3 has strong applicability in Nansi Lake basin.(2) From the parameter rating of the model and sensitivity analysis in the lower lake with WASP7.3, the water temperature, sediment oxygen demand, stream reaeration coefficient and flow are more sensitive to dissolved oxygen. The BOD₅ depletion coefficient, water temperature and flow are more sensitive to biological oxygen demand. Ammonia nitrogen is mainly affected by water temperature, ammonia nitrogen nitrification rate constant and flow.(3) Under the conditions of present pollution discharge, the water quality of the lower Lake also has a gap from the surface water diversion classâ…¢. The main rivers are mainly affected by industrial and urban pollution sources. The total amount of pollutant concentrations are mainly affected by non-point source pollution in the rainy season.(4) In the condition of all water diversion about sewage of status quo, sewage control 1, sewage control 2 and sewage control 3 in the lower lake , NH3-N and BOD₅ in water diversion lake outlet has reached surface water classâ…¢standard basically, The CODcr average concentration is 20.41mg / L, closer to surface water classâ…¢standard. When design water diversion sewage control 3 normally,the CODcr of water diversion lake outlet is, 20.05mg / L, this expressed that river sewage control and river basin environmental governance has a significant success.(5) Some inflow rever in xuecheng xiaosha rever control unit water system in the lower Lake sudden pollution accident is less affected to the lake deterioration of water quality, but large impact to water quality of water diversion lake outlet relatively and has a long affecting time. Among them, industrial pollution sources sudden accident is most seriously under the drought conditions, the impact of wastewater plant run incidents is relatively small to the water quality of water diversion lake outlet. the peak of accidental pollution water quality is near the surface water classâ…¤and the the worst water quality of remaining conditions of the lake outlet water quality can not meet surface water Classâ…¢requirement of Nansi lake in South-North Water Transfer east line project .(6) through analysis of the nutrient status and toxic and harmful substances evaluation of the Nansi Lake, from 1999 to 2008, the overall trend of total nitrogen, total phosphorus concentration is decline. total nitrogen and total phosphorus concentration in Nansi lake in 2008 were an average of 1.288mg / L and 0.088mg / L, the exceeded multiple of total nitrogen and total phosphorus is 0.29 times and 0.76 times respectively,they are closer to the surface water classâ…¢guidelines. In addition, after the poisonous and harmful substances reached the stabilized concentration in Nansi Lake in 2006, water quality relatively superior, all indexs can meet the water requirements of surface water classâ…¢except oil.Take the WASP7.3 water quality simulation analysis of the Nansi Lake as one of the key topics of the water quality control of South-North Water Transfer east line project ,, not only provide scientific decision for decision of Nansi Lake in South-North Water Transfer project and river basin Water Pollution Control Project,and made important theoretical significance and practical value, but also would have a significant environmental benefit, social benefit and economic benefits, promote local economic, social and environmental have a synchronization win-win situation.